Liquid control device

ABSTRACT

A liquid pulsator is described by which a flow of fluid is repeatedly interrupted and delayed and thus converted to a train of liquid pulses. The pulses are formed by opening and closing a valve placed in a fluid flowpath. The embodiments illustrated utilize magnetic forces to accomplish valve actuation and employ a pressure differential across the valve to render the magnetic elements effective. In a cyclic manner, change in the pressure differential across the valve element, incident valve opening and closing, imparts motion to the valve elements from an initial location subsequent to valve closing, and allows the valve elements to be moved to the initial location subsequent to valve opening. A spring stores energy in one direction while delaying fluid flow, and then moves the valve elements to the initial location in the opposite direction during fluid flow. By this expedient, inlet pressure which ordinarily tends to produce only chatter when interrupted by rapid valve opening and closing, is employed to accomplish a more controlled valve actuation.

United States Patent [191 Buchtel Nov. 13, 1973 1 LIQUID CONTROL DEVICE [76] Inventor: Michael E. Buchtel, 22311 Modina,

Lo Guna Hills, Calif. 92653 [22] Filed: Mar. 20, 1972 [21] Appl. No.: 236,051

[52] US. Cl 91/49, 91/50, 91/275 [51] Int. Cl. F01125/08 [58] Field of Search 91/275, 50, 49

[56] References Cited UNITED STATES PATENTS 694,547 3/1902 Hood 91/275 2,231,158 2/1941 Davis 91/275 2,738,956 3/1956 Bielstein 91/50 2,836,395 5/1958 Bielstein 1. 91/50 3,013,531 12/1961 Mueller et al. 91/275 3,236,157 2/1966 Lovell et al 91/50 3,397,619 8/1968 Sturtevant 91/275 3,421,448 l/l969 Brewer et a1. 91/275 Primary ExaminerPaul E. Maslousky Attorneyl-larvey C. Nienow et al.

[5 7] ABSTRACT A liquid pulsator is described by which a flow of fluid is repeatedly interrupted and delayed and thus converted to a train of liquid pulses. The pulses are formed by opening and closing a valve placed in a fluid flowpath. The embodiments illustrated utilize magnetic forces to accomplish valve actuation and employ a pressure differential across the valve to render the magnetic elements effective. In a cyclic manner, change in the pressure differential across the valve element, incident valve opening and closing, imparts motion to the valve elements from an initial location subsequent to valve closing, and allows the valve elements to be moved to the initial location subsequent to valve opening. A spring stores energy in one direction while delaying fluid flow, and then moves the valve elements to the initial location in the opposite direction during fluid flow. By this expedient, inlet pressure which ordinarily tends to produce only chatter when interrupted by rapid valve opening and closing, is employed to accomplish a more controlled valve actuation.

9 Claims, 8 Drawing Figures PATENTED NOV 13 ms SHEET 1 [IF 3' PATENIEDnuv 13 Ian 3.771.420

SHEET 2 [IF 3 LIQUID CONTROL DEVICE This invention relates to improvements in apparatus for producing pulsed liquid flow and to apparatus which is powered by a pulsated flow of liquid.

There are a variety of ways to use force that occurs as a succession of impulses. The reciprocating gasoline engine and the reciprocating pneumatic hammer are examples of well-known devices that utilize force in that form. However, apparatus that employs a pulsating liquid flow to develop and transmit a train of force impulses is less well-known. This is explained by the lack of efficient apparatus for causing liquids to flow in a succession of pulses.

An object of the invention is to provide an apparatus that can produce fluid flow in pulses. It is also an object to provide an apparatus of that kind which has superior characteristics in that turn-on and turn-off occurs more rapidly than has been possible with previous apparatus. It is also an object to provide an apparatus capable of delivering liquid pulses of a large volume at selectable frequency. Another object is to provide an apparatus that permits variability in pulse duration and pulse period, and to do that with sufficient ease and reliability to permit servo control in a feedback system that adjusts pulse frequency.

Further objects of the invention are to provide a liquid pulsator that is relatively inexpensive to produce and whose reliability is high and whose life is relatively long. Additional objects are to provide a motor which incorporates a liquid pulsator and whose output is motion of a mechanical element, and, more simply, to provide an apparatus whose output is a flow of liquid in pulses to be used in cleaning and a variety of other tasks.

These and other objects and advantages of the invention which will hereinafter appear are realized in part by the provision, in combination, of a valve whose valve elements, the head and seat, are relatively displaceable in one direction into and out of position to open and close the valve and at least one which is capable of being displaced in another dimension in a degree that varies with the pressure differential across the valve. These elements are combined with an operating means responsive to displacement of the element in the latter dimension for causing that element to be displaced in the first mentioned dimension when it is displaced in said dimension.

The two different dimensions need not both be linear. One or both can be rotational and in the preferred form of the invention the valve elements reciprocate together in one dimension and they are relatively rotatable in another dimension. The preferred embodiment employs valve elements that are relatively rotatable to open and close the valve and they utilize the pressure differential across the valve to make those elements reciprocate. The reciprocal motion is employed to accomplish the rotational motion that opens and closes the valve. To provide a structure that will utilize that kind of motion is another object of the invention. In that preferred embodiment the valve elements occupy an initial relative rotational position in which the valve is closed. Together they also occupy a position relative to the structure that conducts flow to and from the valve elements. The position they occupy when the pressure differential across the valve is below some given value is also called their initial position relative to the flowpath. If the pressure differential is increased the valve elements are moved in a linear dimension along the flowpath from that initial position to a second position. As an incident to that movement the valve elements are made to rotate so that the valve is open. Opening of the valve results in reduction of pressure across the valve and the valve elements are then returned together to their initial position relative to the flowpath. The return motion results in reorientation of the valve elements so that the valve is closed.

Some means is provided for returning the valve elements together to the initial flowpath position. That means may comprise a spring or the weight of the valve elements themselves or some other structural arrangement. In the preferred embodiment the valve elements are returned to initial condition by a spring.

In the preferred embodiment of the invention, relative rotation of the valve is accomplished magnetically. It is possible to accomplish rotation in one direction magnetically and to accomplish the opposite rotation mechanically. One of the preferred embodiments shown in the drawing employs such a structure. Another preferred embodiment uses magnetic force both to open the valve and to close it. FIG. 8 relates to the first of those embodiments. FIGS. 1, 2, 3, 4, 5 and 6 relate to the other.

The drawings are more particularly described as follows:

FIG. 1 is a view of a motor embodying the invention shown pictorially with part of the motor housing shown sectioned and part of it broken away;

FIG. 2 is a view partly in elevation and partly in section of a fragment of the motor of FIG. 1;

FIG. 3 is a pictorial view of the parts that comprise the fluid pulsator portion of the motor of FIG. 1 including the valve element assembly, the parts being shown exploded;

FIG. 4 is an exploded pictorial view of the parts of the valve element assembly;

FIGS. 5 and 6 are pictorial, schematic views of fragments of the parts of the pulsator showing the relationship between the valve elements, and the magnets that make them rotate, in two different operating conditions;

FIG. 7 is a fragmented sectioned view of a check valve intended for installation downstream from a fluid pulsator when it is necessary to prevent formation of a vacuum;

FIG. 8 is a pictorial fragmented view of the valve element and magnet arrangement employed in an alternative form of the invention.

The liquid motors currently being used are rotary types. To develop an appreciable amount of torque such motors require high pressure and exhibit all of the problems that go with the use of high pressure. Alternatively, they operate at very high turbine speeds and are coupled with reduction gearing. That alternative gives rise to balancing problems, requires precision workmanship, and is generally characterized by high cost. In large sizes rotary turbines are used as prime movers for electrical generators and in the smaller sizes they are used in connection with surgical and dental tools. Heretofore it has not been practical to use liquid pulsing in powering motors. Probably the most complex and most troublesome problem in such an attempt is the phenomena water-hammer. Water-hammer occurs when a column of liquid flowing at one velocity along a confined path has its motion arrested. The difficulty can be alleviated in part by the use of accumulators and resilient elements in which momentum forces can be stored for dissipation over a longer period. But those expedie'nts add cost, weight, complexity and size to the motor system to achieve an adequate solution to the water-hammer phenomena.

The motor shown in FIG. 1 does not suffer from water-hammer. It makes very little noise. Pressurized fluid enters at the input conduit 12. It flows through the body of the motor into the end housing 14 where it escapes through outlets 16. When the motor operates, an internal structure is made to reciprocate. In this embodiment that structure, 18, is connected by a wrist pin to a connecting rod 22 which drives-a counterbalanced crank 24 to rotate the output shaft 26.

The speed of rotation of the shaft 26 can be altered by altering the applied fluid pressure, or volume, or by altering the volume of fluid that passes through outlets 16. In the embodiment shown, reciprocation of the internal structure is initiated by rotating control sleeve 28 relative to the rest of the structure in a clockwise direction. The control sleeve fits tightly over a cam sleeve 30. The sleeve 30 is provided with a hole 1 l and it may be seen in FIGS. 2 and 3. Slots 31 are used for applications to be discussed later. A pin 34 (shown only in FIG. 2) is fixed to a magnet 36 at hole 11. That pin extends through the radial leg of guide slot 38 in the guide sleeve 40 and then into hole 11 of cam sleeve 30. The sleeve 28 is press-fitted on the cam sleeve 30, as mentioned above, and consequently they rotate together to rotate magnet 36. The outer sleeve 28 is used for its aesthetic value and to cover the slot 31 and hole 11. This arrangement permanently fixes the axial position of magnet 36 relative to magnet 42, to be discussed later, and thereby determines the stroke of the reciprocating internal structure such that it is synchronous with the throw of crank 24 (see FIG. 1) when magnet 36 is rotated as previously discussed.

The list of parts includes a second magnet 42 which is similar to the magnet 36. It includes a bore 44 at its side in which a pin 46 is inserted. The pin is visible only in FIG. 2 where it is shown toextend into an opening in the sleeve 40. The pin 46 engages with hole 48 and that can be seen in FIG. 3. A similar hole perforates the sleeve 41}! diametrically from hole 48. It will be apparent that slot 31 and hole ll 1 are duplicated on the other side of cam sleeve 30 and that the guide slot 38 is duplicated on the other side of the inner sleeve 40.

The lower left end (in the drawings) of the inner guide sleeve 40 has reduced diameter and is provided with internal threads by which it is threaded on the end of an externally threaded end cylinder 50. The upper end of that end cylinder is fitted with diametric holes 52 that may be seen in FIG. 3. Just above, in FIG. 3, two screws 54 are shown positioned opposite holes in a flow pipe 56. The end cylinder 50 is assembled over the flow pipe and the screws 54 are inserted through the openings 52 and are threaded into the openings of flow pipe 56. The screws are long enough so that they extend into the interior of flow pipe 56 sufficiently far to engage the upper end of return spring 58 which can be seen at the upper end of axial slot 74 in cylinder 60. Returning to FIG. 2, one of the machine screws 54 is shown extending through the end cylinder 50 into the flow pipe 56 to engage spring 58.

At the other end of FIG. 2 (at its left end in the drawings) the crankshaft housing 14 is attached by a number of machine screws to a mounting ring 62. The mounting ring (see FIG. 3) is provided with diametric bayonet slots 64 which engage with a pair of pins that extend inwardly from the walls of the guide sleeve 40. One of those pins is visible in FIG. 3 where it is numbered 66. The housing 14 and its parts are assembled onto the pulsator unit as shown in FIG. 2 by completing that bayonet connection.

While the details are not shown in the drawings, the member 18 connects to the end of a shaft that is seen to extend from the upper end of valve element assembly 71. In operation of the device, the valve elements and that shaft 70 reciprocate relative to the flow pipe 56 and the sleeves 50, 40 and 30 and 28 and relativeto housing 14 whereby a reciprocating motion is imparted to the member 18. The reciprocating motion is converted to rotational motion by the connecting rod 22 and crank 14.

The parts that are assembled together to make the valve element assembly 71 are shown exploded in FIG. 4. The spring 58 is housed within a tubular member 60 whose lower end is rolled inwardly at 72 to form a shoulder for the lower end of the spring to bear against. The spring is shown in relaxed condition in FIG. 4. Its diameter is such that it can becompressed down in the tube. When it is assembled within the tube 60, and when the machine screws 54, previously discussed, are turned in place, tne ends of those machine screws 54 will extend through the elongated slot formed by slot wall 74 and they will rest atop the topmost coil, 76, of the spring. As a result, the tube 60 is secured against rotation relative to elements 50, 56 and 40 but it is free to move along the axis of those elements as the spring 58 is first compressed and then relaxed.

At its upper end the tube 60 is notched at four places whereby four ears are formed as extensions of the tubing wall. They are equally spaced around the circumference of the tube and each is perforated to receive a fastener by which a flow dividing spider 78 is affixed to the interior of the tubing at its upper end. The spider is provided with four spokes, one to be connected to a respectively associated one of each of the four ears. Thus, spoke 79 is to be attached to ear 80. The lower edge of each spoke is tapered so that minimum turbulence is experienced by fluid which will flow into the lower end of flow pipe 56 and into the interior of tube 60 there to be divided into four streams each flowing between a different pair of the spokes of the spider 78. The shaft 70 extends from the spider 78 in the direction of flow. It has been broken off for the sake of clarity in FIG. 4 in view of its length. Element 81 is the valve seat. It is a cup-shaped member having its open end facing the spider 78. Its sidewalls are notched with notches that are just wide enough to accommodate the ears 80. A central opening 88 in its bottom wall permits the seat to be slipped over the shaft 70. It is pushed down on shaft 70 until its sidewalls, now divided into four downwardly extending wall sections, are pushed down to lie between the ears of the cylinder 60. One wall section is identified by the reference numeral 82.

This assembly may be viewed in FIG. 3. The spoke 79 is disposed immediately under the ear 80 and the wall sections 82 are disposed between the ears 80.

Returning to FIG. 4, the bottom wall of the cupshaped valve seat 81 is provided with four perforations 86 in addition to the central shaft opening 88. The four openings 86 are wedge-shaped and in assembled condition lie immediately above the flow space between a respectively associated pair of adjacent spider spokes.

The valve head is the next element. It is identified by the reference numeral 90 and its shape is identical with that of the seat 81 except that it is assembled with its open end upwardly away from seat 81. It has a central opening in its bottom (not visible in the drawing) through which the shaft 70 extends. The bottom wall is also provided with four perforations, three of which are visible and are identified by the reference numeral 92. When the head and seat have the relative rotational position shown in FIG. 4 openings 86 match openings 92 and liquid may flow upwardly between the spokes of the spider 78 through openings 86 and through openings 92.

The next element 94 is a four pole magnet. It has the form of a right cylinder whose outer diameter is substantially equal to the outer diameter of cup 90 and which has had four sections of its periphery cut away to form a cross. One of the legs is numbered 96 for identification. The legs have a width and are spaced so that they can be inserted into the four notches of the valve head 90. Those notches divide the sidewall of the valve head 90 into four upstanding wall sections, two of which have been numbered for identification. One has been numbered 100 and the other is numbered 102. The magnet 94 is assembled on the valve head 90 such that the arm 96 extends between head wall sections MM) and 102. Thus assembled, liquid flowing through openings 92 is free to flow through the cutaway space between adjacent pairs of the legs of the magnet. This can be seen in FIG. 3 where arm 96 is shown disposed between wall sections 100 and 102.

The central, through opening 104 of the magnet and the central bottom opening of the valve head 90 are of diameters sufficient to permit the head and magnet combination to rotate freely together on the shaft 70. They are secured in place on shaft 70 by the combination of a ball bearing and a lock nut 110. The ball bearing comprises an upper and lower thrust washer 112 and 114, respectively, between which is sandwiched the ball bearing race 116. The lock nut 110 is tightened down so that the magnet and valve head assembly lie against the upper surface of the valve seat 81 without being so tight as to impede free rotation of the valve head.

When the valve head and seat have the relative rotational orientation depicted in FIG. 4, fluid is free to flow through the valve element assembly. The seat 81 cannot rotate, but the head 90 can, and when it is rotated from the position shown, the area of opening 92 that overlap the area of opening 86 is diminished and flow is impeded. When the head has been rotated through an angle of 45, flow will cease. The head is made to rotate through an angle of 45 by an interaction between magnet 94 and the two magnets 36 and 42 which are supported by the flow tube 56. The position of the upper, stator magnet 42 is fixed. The lower, control magnet 36 can be moved to change its spacing from magnet 42. For the moment, however, it is assumed that the two magnets have the spacing depicted in FIGS. 2, 3, 5 and 6. These figures omit the guide sleeve 40 and they have portions of the substantially non-magnetic flow tube 56 cut away so that the head and seat of the valve element assembly are visible. In

FIG. 5, a portion of the upper end of the flow pipe 56 is cut away to reveal that the valve head occupies a location along the pipe axis where it is approximately concentric with the stator magnet 42. In FIG. 6, a portion of the flow tube 56 is cut away in the vicinity of the control magnet 36 to show the valve head 90 in a retracted or initial position where it is approximately concentric with the control magnet 36. Not only has the position of the valve element assembly been changed so that the valve head lies within magnet 42 in one view and lies within magnet 36 in the other view, it will be observed that the rotational position of the valve head 90 differs by 45 in the two views. In FIG. 5, wall section 102 of the valve head is opposite wall section 82 of the valve seat. In FIG. 6, wall section 102 of the valve head lies one-eighth turn from its FIG. 5 position. The reason for the rotation is best seen in FIGS. 5 and 6 where the several poles of the two magnets 42 and 36 are indicated by the letters N for North pole and S for South pole. The two magnets 36 and 42 are assembled so that the south poles of one has the radial position of the North poles of the other. When the valve head and seat have the relationship depicted in FIG. 6, the valve is closed. During valve closure, pressurized fluid entering the upstream end of flow pipe 56 (the lower end of the pipe in FIG. 3) moves seat 81 slightly downstream such that the juxtaposed faces of seat 81 and head 90 bear against each other with an increasing force until the instant of closure at which time rotational inertial force of head 90 and magnet 94 is arrested and the pressurized fluid cannot pass through the valve elements, nor can the fluid pass around, because the valve seat 81 has a sliding fit inside the flow pipe 56 whereby fluid cannot flow around the seat. The pressure of the fluid acting on the valve elements in this manner, seals the valve and urges the valve assembly 71 to move in the downstream direction. This movement is opposed by spring 58 in a degree that increases with the degree of displacement substantially according to Hookes haw, because the spring 58, being restrained at its upper end by the screws 54, and bearing against the tube 60 at its other end, tends to force the tube 60 in the upstream direction. In any case, motion of the valve elements in the flow pipe 56 effects an action or reaction of the spring, since those elements are attached to tube 60 by means of the spider 78, shaft 70, and nut 110, as previously discussed. When the valve assembly is thus moved downstream, the magnet 94 leaves the influence of control magnet 36 and enters into the field of magnet 42 as shown in FIG. 5. The poles of magnet 42 being displaced, the head magnet 94 and the head 90 are then rotated through an angle approaching 45. As they rotate, the openings in the bottom wall of the head rotate and form a flowpath with the openings of the seat. As a consequence, fluid pressure behind the valve assembly is relieved. As this pressure falls, it be comes less than the force stored in spring 58, and the spring urges the valve assembly back toward initial position. As the valve element assembly moves toward initial position, the magnet of the valve head leaves the influence of the stator magnet 42 and enters again into the influence of the control magnet 36 (see FIG. 6) whereby the head is oriented in a direction to close the valve. The valve, having been closed, supply pressure again forces the valve element assembly downstream, and the cycle is repeated.

It will be apparent that the frequency at which the valve elements reciprocate along the flowpath, and therefore the frequency of pulse formation, depends in part upon the pressure to which the device is subjected, and it depends upon the spring rate of spring 58. The latter is ordinarily fixed, and only slight variations in pulse frequency occur with gross variations in supply pressure; howevenfrequency can be made constant by the use of regulating valves or other means to insure a uniform source pressure. It may be desirable to adjust operating frequency during operation, or independently of supply pressure, and the embodiments selected for illustration in the drawing include a means by which these objectives are accomplished easily and reliably. It will be readily apparent that operating frequency can be readily changed by changing the axial spacing between the stator and the control magnet. If the'control magnet, the one that is closer to the initial position of the valve elements, is fixed and the other magnet, the stator magnet, is made movable, the frequency is simply a function of the spacing between the two of them because that determines how far the valve elements must be moved to initiate rotation from valveopen to valve-closed position. That structural arrange ment is easily envisioned and is easy to understand. The drawings, however, depict the more sophisticated alternative. Referring to FIG. 3, it will be seen that it is the stator magnet whose position is fixed in this embodiment whereas the control magnet, the one closest to what has been termed the initial position of the valve elements, is movable. Axial movement of the control magnet away from initial condition results in rotation to valve-closed position before the head is moved to a position in which the spring 58 is fully extended. Therefore, the bias of the spring at valve-closed position is changed when the position of the magnet 36 is changed. Since frequency depends upon the force of the return spring and also depends upon the spacing between the magnets, 36 and 42, frequency is now determined by two interrelated factors. In practice, making the upstream magnet 36 movable provides additional control in thatpulsing action, or continuous flow may be selected by means which will be more fully discussed later.

Any of a number of arrangements can be employed to change the position and location of the magnet 36. The one selected for illustration in the drawings is particularly advantageous. The magnet 36 is mounted upon a plurality of pins that extend radially from holes 37 through slots 38 of the guide sleeve 40 into cam slots 31 of the cam sleeve 30. Guide slots 38 are L-shaped. When the pins 37 are disposed in the lower leg of the Us, the magnet 36 can be rotated so that its pole are substantially aligned with the poles of the stator magnet 42. Having thus been rearranged, the magnet 36 does not cause the valve head to rotate in the flowpath. The valve head is opened and remains in open position so that there is no pulsing action and flow through the unit is continuous. If the cam sleeve 30 is now rotated clockwise (in FIG. 3) the pins 37 will be carried clockwise along the lower leg of the L-shaped slots until they reach the clockwise end of those lower legs. At which time, the control magnet causes the head to rotate in the flowpath to the valve-closed position and pulsing action begins. Further rotation of the cam sleeve 30 will cause the pins 37 to be cammed upwardly along the cam surfaces 32 of slots 31. The pins 37 being confined by the upper leg of the L-shaped guide slots 38, the pins are moved downstream carrying the magnet 36 with them to a position closer to the stator magnet 42 in accordance with the degree in which the cam sleeve 30 is rotated. In the assembled condition sleeve 28 is press-fitted down over the sleeve 30 and rotation of the cam sleeve is accomplished by rotating the sleeve 28.

The major advantage of using magnets to accomplish head rotation lies'in the fact that no mechanical con nection is required; consequently, wear and noise are reduced. Another advantage of the elimination of mechanical connections to actuate the valve, is that peak pressures, caused by instantaneous valve closure, are readily dissipated by spring 58, and the resultant shock caused by instantaneous cessation of flow is made negligible by permitting the entire valve to move at approximately the same fluid velocity after valve closure as the velocity of the fluid following valve opening. Another advantage lies in the fact that the shape of the magnetic field through which the head rotating force is transmitted varies with the position of the head (more particularly with the position of the head magnet 94). A hysteresis effectis created whereby head rotation occurs over a shorter head displacement than would otherwise be true, resulting in faster turn-off and turn-on speed without affecting pulse or pulse period duration. The flux density between the stator, or control magnet and the head magnet is considerably greater than that of a stator, or control magnet and a ferromagnetic head, and this is one of the reasons why the preferred embodiment employs a magnet for valve head actuation. Nonetheless, there are some embodiments in which it is preferred that the turn-on and turn-off characteristics be different. That can be accomplished by using a magnetic means to perform one task and a mechanical means to perform the other. An example is illustrated in FIG. 8. In this case, only the control magnet 36 is employed. Magnet 42 is omitted. The structure of tube 60 need not be changed and the tab is identified in FIG. 8 to indicate that in this embodiment the tube seat is, in fact, unchanged. Seat 81 is unchanged. Shaft 70 is unchanged and the magnet 94 is unchanged. The flow pipe 56 is changed by the addition of a pair of cam pins 200, both of which are shown connected at the upper end of the modified flow pipe 256. The valve head is also changed. The head in FIG. 8 is identified by the reference numeral 290. Like its counterpart, head in the other figures, it is provided with four notches in which the ends of the magnet 94 are received. Two of the wall sections between the magnet legs are like those of head 90, but the other two are cut off on a bias to form a cam face. These cam faces are designated by the reference numeral 292, and all of one, and part of the other is visible in FIG. 8. The condition depicted in that figure has the valve elements in an intermediate position. The valve is closed. Previously, the valve elements were retracted downwardly (in FIG. 8) to a position in which the valve head was rotated by magnet 36 to the valve-closed position. The head remains in that position and is shown at a time when it is moving upwardly. No force has been applied to the head to make it rotate and it remains in valveclosed position. It will be apparent, however, that as it is driven upwardly by fluid pressure from below, the head will reach a position in which the cam'surfaces 292 engage the cam pins 200. The pins being fixed, and the cam surfaces 292 being a part of the rotatable head,

the head is caused to rotate to valve-open position. Upon the head being opened, the pressure differential across the valve is reduced and the valve elements are returned toward initial position by the bias spring, not shown.

The motor shown in FIG. 1 has exhaust openings 16 near the valve element so that neither back pressure nor creation of a vacuum presents a problem to its operation. That may not be true, however, in other applications. One major application for pulsating liquid lies in its use as a cleaning expedient. In that application it may be desirable to place the pulsator at some distance from the discharge end of the apparatus. In that circumstance, the integrity of the liquid pulse is preserved by spacing them with a volume of air. Air may be introduced into the system through a check valve placed immediately after the pulse so that air is drawn into the flowpath downstream from the pulsator unit in the interval between pulses when the head is in the valveclosed position. A suitable arrangement is depicted in FIG. 7.

FIG. 7 illustrates a method of employing the reciprocating motion of the valve-assembly to operate an air pump which performs several functions. First, the pump provides a rapid vacuum relief after valve closure and it produces a driving pressure for impelling incompressible fluids downstream and for expelling incompressible fluids through small orifices. The amount of force required to operate the pump can be easily adjusted to provide various duty cycles by means of a needle valve. Also, the intrinsic operating resistance of the pump permits the valve-assembly to travel a shorter distance for a given time period, thereby reducing the physical size and spring rate of the return spring as well as the size of the unit. In addition, the shock absorbing effect of the pump couples with the resiliency of the spring to provide smooth, quite operation. Finally, the pump may be further utilized to siphon and meter a substantial quantity of liquid such as soap, bath oil, paint, etc. from a suitable reservoir; atomize this liquid with intake air, then discharge the resultant mist into the stream of each pulse.

The open end of piston 305 faces downstream and its outer wall has a sliding fit inside body 306. Body 306 is made of a low friction, semi-rigid material such as plastic and takes the form of a thin wall cup whose mouth faces upstream to receive piston 305. The body 306 is positioned concentric with the piston and mounted to pipe 56 by means of an air intake pipe 307 which passes through pipe 56 and body 306 and seats firmly into recesses formed in a boss 310 extended inwardly from the base of body 306. Holes at the bottom of each recess extend into a larger hole centered in the boss to permit the passage of air into the pump body. A ball 309 is snapped into flexible fingers formed in one end of the boss and the other end is threaded to accommodate a needle valve 308 for regulating air intake volume. It should be noted that the needle valve may be placed at either end of the air intake scheme depending on access requirements or eliminated en tirely for a fixed duty cycle.

FIG. 7 shows a cross-sectional view of the air pump. In this view the valve elements are closed and the valveassembly is being pushed downstream by the pressurized operating liquid, as previously discussed. The air pump can be seen to comprise two primary members, a piston 305 and a piston cylinder or body 306. Piston 305 takes the form ofa cup at the end of a partially hollowed shaft 70A which supports the valve elements in the same manner as shaft 70 of FIG. 4, previously discussed. The hollow portion 304 of the shaft 70A is 5 cross-drilled at right angles to the shaft to form holes 302 which are radially alignable with a complimentary number of holes 30] extending through the body of magnet 94A at each fillet when magnet 94A is in the closed position shown.

The elements of FIG. 7 are shown at a time when the valvehead 94A is rotated so that the main valve is closed. Upstream pressure has moved the valveassembly part way downstream and the head magnet 94A is passing from the influence of the control magnet toward the influence of the stator magnet. In that condition, the holes 302 of shaft 70A are aligned with the holes 301 of the head 94A. Piston 305 moves downstream with the valve-assembly into the cylinder or pump body 306 reducing the volume within the cylin der and forcing air through opening 304 of shaft 90A and through openings 302 and 301 into the flow spaces of the head from whence it flows downstream. It flows downstream behind the body of fluid previously released through the valve forcing that body of fluid along the flowpath and maintaining the pressure within the flowpath so that no vacuum and attendant problem is created.

The supply of air in cylinder 306 is replenished on the return stroke of the valve element. On the return stroke, the magnet 94A will have been rotated to close the flowpath through openings 301 and 302. Air is drawn into cylinder body 306 through the check valve 310. Air, which may be combined with soap or other materials, is drawn in through the flow pipes 307 into the interior of the check valve and past the ball check 309. The amount of air and other material that can be drawn in through the flow pipes 307 is controlled by the needle valve 308.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art.

I claim:

1. In combination:

a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valveclosed condition;

said elements being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve; and

operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension;

said operating means comprising magnetic means for urging said head and seat from one relative position to another in said one dimension when those elements occupy one position in said second dimension and return means for urging said head and seat to said relative position in said one dimension when those elements occupy another position in said second dimension;

said magnetic means comprising three magnetic members, one carried by one of said valve ele iii ments, and a second fixed in both of said dimensions, and a third spaced from one of said first and second magnetic elements in both of said dimensions whereby said one of said valve elements experiences a force tending to move it in said one dimension as an incident to movement of the salve elements in said second dimension.

2. In combination:

a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valveclosed condition;

said elements being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve;

operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension;

said operating means comprising magnetic means for urging said head and seat from one relative position to another in said one dimension when those elements occupy one position in said second dimension and return means for urging said head and seat to said relative position in said one dimension when those elements occupy another position in said second dimension; and

a housing defining a flowpath for fluid, said valve elements being included in said flowpath and being mounted for movement together in the direction of said fiowpath, and for relative rotational movement about an axis extending in said direction, the valve being opened in one relative rotational position of the elements and closed in another;

said magnetic means comprising a first magnetic member carried by one of the valve elements and a second magnetic member carried by the housing such that said magnetic members are mutually effected magnetically when the valve elements ccupy one position along the flowpath sufficient to force rotational displacement of said one valve element.

3. The invention defined in claim 2 in which said return means comprises another magnetic member carried by one of said housing and one valve element such as to experience mutual magnetic effect with the magnetic member on the other sufficient to force a different rotational displacement of said one valve element when the valve elements occupy another position along the flowpath.

4. In combination:

a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valveclosed condition;

said elements being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve;

operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension;

means for subjecting said valve to fluid pressure; and

means for converting reciprocating motion of said elements in said second dimension to rotary motion;

said second dimension being longitudinal and said first dimension being rotational about the longitudinal dimension, one valve element being magnetic and polarized and rotatable about the line on which the valve elements are longitudinally movable;

said operating means comprising a magnetic element coupled magnetically to said one valve element when the valve elements are displaced together in said second dimension.

5. In combination:

a valve comprising a seat and a head and a flowpath for liquid flowing past the seat and head;

head moving means for causing the head to move in one dimension in response to change in differential pressure across the valve;

valve operating means responsive to head movement in said one dimension for effecting valve opening and valve closing as an incident to movement in said one dimension;

the valve comprising a housing in which said flowpath is formed and in which said valve operating means comprises three'magnets one carried by the head and two carried by said housing at spaced points along said one dimension in which the head is movable together with means for altering the spacing between said two magnets.

6. The invention defined in claim 5 in which said housing comprises an elongate flowpipe the head and seat comprising generally cylindrical members mounted end to end and relatively rotatable on a common axis and having a sliding fit within said flow pipe, the two magnets being mounted at the exterior of the flowpipe and relatively movable in the direction of its axis.

7. The invention defined in claim 6 which further comprises a means secured to said head and seat members for converting reciprocation motion to rotational motion.

8. The invention defined in claim 5 in which said housing comprises a pipe whose bore defines said flowpath, the head and the seat being arranged in series in said flowpath; said head moving means comprising means for connecting the head and seat for movement together along the flowpath while permitting rotational movement of the head relative to the seat and pipe, said head moving means further comprising means in the form of a spring for urging said head and seat to an initial upstream position in the pipe, said head and seat having dimensions to extend entirely across said flowpath whereby upstream pressure tends to force the head and seat downstream when the head closes the seat;

said housing further comprising a cylindrical member surrounding the pipe, said two magnets being carried by said cylindrical member at points spaced apart in the direction of its axis;

said invention further comprising means for altering the amount by which said magnets are spaced.

99. In combination:

a valve comprising a seat and a head and means defining a flowpath for liquid flowing past the seat and head;

head moving means for causing the head to move in one dimension in response to change in differential pressure across the valve;

valve operating means responsive to head movement in said one dimension for effecting valve opening in the form of a cam and cam follower for rotating the head when moved in one direction along said flowpath, said magnetically attracted elements acting to rotate the head when the head is moved in the opposite direction along the flowpath. 

1. In combination: a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valve-closed condition; said elemEnts being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve; and operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension; said operating means comprising magnetic means for urging said head and seat from one relative position to another in said one dimension when those elements occupy one position in said second dimension and return means for urging said head and seat to said relative position in said one dimension when those elements occupy another position in said second dimension; said magnetic means comprising three magnetic members, one carried by one of said valve elements, and a second fixed in both of said dimensions, and a third spaced from one of said first and second magnetic elements in both of said dimensions whereby said one of said valve elements experiences a force tending to move it in said one dimension as an incident to movement of the salve elements in said second dimension.
 2. In combination: a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valve-closed condition; said elements being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve; operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension; said operating means comprising magnetic means for urging said head and seat from one relative position to another in said one dimension when those elements occupy one position in said second dimension and return means for urging said head and seat to said relative position in said one dimension when those elements occupy another position in said second dimension; and a housing defining a flowpath for fluid, said valve elements being included in said flowpath and being mounted for movement together in the direction of said flowpath, and for relative rotational movement about an axis extending in said direction, the valve being opened in one relative rotational position of the elements and closed in another; said magnetic means comprising a first magnetic member carried by one of the valve elements and a second magnetic member carried by the housing such that said magnetic members are mutually effected magnetically when the valve elements occupy one position along the flowpath sufficient to force rotational displacement of said one valve element.
 3. The invention defined in claim 2 in which said return means comprises another magnetic member carried by one of said housing and one valve element such as to experience mutual magnetic effect with the magnetic member on the other sufficient to force a different rotational displacement of said one valve element when the valve elements occupy another position along the flowpath.
 4. In combination: a valve including as valve elements a head and a seat, the elements being relatively displaceable in one dimension into and out of valve-open and valve-closed condition; said elements being displaceable together in a second dimension from an initial position in a degree variable with the pressure differential across said valve; operating means responsive to displacement of said elements in said second dimension for causing said elements to be displaced in said one dimension when displaced in said second dimension; means for subjecting said valve to fluid pressure; and means for converting reciprocating motion of said elements in said second dimension to rotary motion; said second dimension being longitudinal and said first dimension being rotational about the longitudinal dimension, one valve element being magnetIc and polarized and rotatable about the line on which the valve elements are longitudinally movable; said operating means comprising a magnetic element coupled magnetically to said one valve element when the valve elements are displaced together in said second dimension.
 5. In combination: a valve comprising a seat and a head and a flowpath for liquid flowing past the seat and head; head moving means for causing the head to move in one dimension in response to change in differential pressure across the valve; valve operating means responsive to head movement in said one dimension for effecting valve opening and valve closing as an incident to movement in said one dimension; the valve comprising a housing in which said flowpath is formed and in which said valve operating means comprises three magnets one carried by the head and two carried by said housing at spaced points along said one dimension in which the head is movable together with means for altering the spacing between said two magnets.
 6. The invention defined in claim 5 in which said housing comprises an elongate flowpipe the head and seat comprising generally cylindrical members mounted end to end and relatively rotatable on a common axis and having a sliding fit within said flow pipe, the two magnets being mounted at the exterior of the flowpipe and relatively movable in the direction of its axis.
 7. The invention defined in claim 6 which further comprises a means secured to said head and seat members for converting reciprocation motion to rotational motion.
 8. The invention defined in claim 5 in which said housing comprises a pipe whose bore defines said flowpath, the head and the seat being arranged in series in said flowpath; said head moving means comprising means for connecting the head and seat for movement together along the flowpath while permitting rotational movement of the head relative to the seat and pipe, said head moving means further comprising means in the form of a spring for urging said head and seat to an initial upstream position in the pipe, said head and seat having dimensions to extend entirely across said flowpath whereby upstream pressure tends to force the head and seat downstream when the head closes the seat; said housing further comprising a cylindrical member surrounding the pipe, said two magnets being carried by said cylindrical member at points spaced apart in the direction of its axis; said invention further comprising means for altering the amount by which said magnets are spaced.
 9. In combination: a valve comprising a seat and a head and means defining a flowpath for liquid flowing past the seat and head; head moving means for causing the head to move in one dimension in response to change in differential pressure across the valve; valve operating means responsive to head movement in said one dimension for effecting valve opening and valve closing as an incident to movement in said one dimension; said valve operating means comprising magnetically attracted elements one carried by the head and movable with it and the other carried by said means defining a flowpath; said valve operating means further comprising means in the form of a cam and cam follower for rotating the head when moved in one direction along said flowpath, said magnetically attracted elements acting to rotate the head when the head is moved in the opposite direction along the flowpath. 